1. Field of the Invention
The present invention relates to the displaying of graphics objects such as text or sprites overlaying a multimedia television presentation, and more specifically to the display of animated graphics or play out of video or audio coordinated with a multimedia presentation.
2. Description of Prior Art
Many video applications, including interactive and multimedia applications, take advantage of the video viewer's equipment capability to display graphics overlays on the video screen such as a TV or a PC monitor. These graphics displays either dominate the entire screen, as in the case of many electronic program guides or menus, or sections thereof. The video behind these graphic overlays is entirely or partially obscured, thereby interfering with the viewing experience. Systems for the presentation of electronic program guides, such as described in U.S. Pat. Nos. 5,737,030, 5,592,551, 5,541,738, and 5,353,121, display these guides either on a screen devoid of video or one which uses a still frame or moving video simply as a background, with no coordination between the location of items in the video and the location of graphics overlays.
Currently, Viewers' equipment, such as set-top boxes (STB), does not have the capability to determine where objects are located in the video. Determination of object's location in a video is necessary in order to place the graphics objects, such as the on-screen text or animate characters, in locations which do not interfere with objects appearing in the video presentation.
Systems such as the one described in U.S. Pat. No. 5,585,858 attempt to coordinate video and graphic displays by including in the broadcast stream, or pre-storing at the viewers' equipment, graphic overlay screens designed to be compatible with the video content. However, these screens must be created well in advance of the presentation, and thus lack the flexibility to create and display non-interfering graphics overlays adaptively. In addition, those systems display graphics at specific "trigger points" in the presentation, not at arbitrary points throughout the presentation.
Other systems which add graphics or audio content to an existing presentation, such as described in U.S. Pat. No. 5,708,764, require the active participation of the viewer in the process of presentation. The viewer, for example, may be required to answer a number of questions before or during the presentation, the responses are then displayed on the screen at predetermined times.
Systems which allow the personalization of content for individual users are well known in the context of Web browsing. Other systems, such as systems described in U.S. Pat. Nos. 5,585,858 and 4,616,327, provide a limited number of introductions, by the viewers' equipment of predetermined text or graphics. Some systems, such as described in U.S. Pat. Nos. 4,839,743, 4,786,967, and 4,847,700, provide audio and/or video personalization through the selection among a small number of alternate video and audio tracks which are broadcast simultaneously. The selection is performed at the viewer's equipment.
What is needed is a system whereby the location and timing of video objects and audio events are made available to the viewers' display equipment, giving that equipment the flexibility to add non-interfering graphics or audio when and where it sees fit, in an adaptive manner throughout a presentation, rather than at limited points. This ability will allow the viewers' equipment to create a tandem video/audio/graphics presentation without requiring viewers' active participation in the presentation process. That system must allow coordination of graphics content that is not pre-stored, such as broadcast news bulletins, and perform still or animated graphics overlay of video, addition or replacement of video, and audio replacement in coordination with the existing video and audio content of a presentation.